On 12/12/2018 12:17 AM, James Morris wrote:
On Sun, 9 Dec 2018, Nayna Jain wrote:
+/*
+ * Blacklist an X509 TBS hash.
+ */
+static __init void uefi_blacklist_x509_tbs(const char *source,
+ const void *data, size_t len)
+{
+ char *hash, *p;
+
+ hash = kmalloc(4 + len * 2 + 1, GFP_KERNEL);
+ if (!hash)
+ return;
+ p = memcpy(hash, "tbs:", 4);
+ p += 4;
+ bin2hex(p, data, len);
+ p += len * 2;
+ *p = 0;
+
+ mark_hash_blacklisted(hash);
+ kfree(hash);
+}
+
+/*
+ * Blacklist the hash of an executable.
+ */
+static __init void uefi_blacklist_binary(const char *source,
+ const void *data, size_t len)
+{
+ char *hash, *p;
+
+ hash = kmalloc(4 + len * 2 + 1, GFP_KERNEL);
+ if (!hash)
+ return;
+ p = memcpy(hash, "bin:", 4);
+ p += 4;
+ bin2hex(p, data, len);
+ p += len * 2;
+ *p = 0;
+
+ mark_hash_blacklisted(hash);
+ kfree(hash);
+}
These could be refactored into one function.
Thanks James for reviewing.
Yes, the code should be refactored. However, I think making it a single
function would require adding a new field to the function callback
definitions as well. Probably, a simpler approach would be to define a
common function uefi_blacklist_hash(...) which can then be used by the
two functions uefi_blacklist_x509_tbs(...) and
uefi_blacklist_binary(...). These two functions now act as wrapper
functions. Below is the example code:
+/*
+ * Blacklist a hash.
+ */
+static __init void uefi_blacklist_hash(const char *source, const void
*data,
+ size_t len, char *type, size_t type_len)
+{
+ char *hash, *p;
+
+ hash = kmalloc(type_len + len * 2 + 1, GFP_KERNEL);
+ if (!hash)
+ return;
+ p = memcpy(hash, type, type_len);
+ p += type_len;
+ bin2hex(p, data, len);
+ p += len * 2;
+ *p = 0;
+
+ mark_hash_blacklisted(hash);
+ kfree(hash);
+}
+
+/*
+ * Blacklist an X509 TBS hash.
+ */
+static __init void uefi_blacklist_x509_tbs(const char *source,
+ const void *data, size_t len)
+{
+ uefi_blacklist_hash(source, data, len, "tbs:" , 4);
+}
+
+/*
+ * Blacklist the hash of an executable.
+ */
+static __init void uefi_blacklist_binary(const char *source,
+ const void *data, size_t len)
+{
+ uefi_blacklist_hash(source, data, len, "bin:" , 4);
+}
Thanks & Regards,
- Nayna
